Rent a pipe cutter. (post #206997, reply #3 of 5)

But in theory the hazard is that combustable vapors will be released as the pipe is heated. So you could either heat the pipe and vent off the vapors before cutting or somehow keep the pipe cool while cutting. Hard to say how much of either is enough, though (or even how serious the hazard is to begin with).

Another option is to fill the pipe with nitrogen or CO2.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed. --Herman Melville

Also note that the hazard is (post #206997, reply #5 of 5)

Also note that the hazard is from an explosion in a "relatively" tightly sealed enclosure. If there is a way to vent the pipe (eg, uncouple a union or remove a plug) within a few feet and also vent or disconnect (via valve or coupling) the rest of the pipe then the worst you'd get is a "pop". And, of course, vent the area where you're working -- windows open, fan running.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed. --Herman Melville